1) Field of the Invention
This invention relates to novel physiologically-active compounds exhibiting pesticidal effects including insecticidal, acaricidal, nematocidal and anthelmintic effects and also to production processes thereof.
2) Description of the Related Art
Needless to say, agrochemicals are indispensable for stably maintaining high agricultural harvest. It is however not possible to deny the possibility that they may remain in crops and may develop problems such as toxic hazard to human bodies and environmental contamination. There is hence a demand for the development of agrochemicals having still higher safety. With a view toward developing still safer agrochemicals, the present inventors have carried out an investigation while paying attention to pesticidal products.
As insecticidal substances available from microorganisms, there have been known cyclic peptides led by destruxin produced by a mold fungus, [Agricultural Biological Chemistry, 26, 36 (1962)]; crystalline proteins such as .delta.-endotoxin produced by a bacterium of Bacillus [Annual Review of Entomology, 12, 289 (1967)]; pyrones such as piericidin produced by an actinomycete [Agricultural Biological Chemistry, 30, 517 (1966)]; macrolide substances represented by tetranactin classified under the group of electron transport inhibitors, macrotetrolides, containing pyrrolidone as a nucleus [The Journal of Antibiotics, 24A, 418 (1971)], milbemycin having a structure similar to the compounds of this invention [Japanese Pat. Laid-Open No. 32481/1981; U.S. Pat. No. 4,346,171], avermectin [U.S. Pat. No. 4,199,569]; etc.